Stable isotopes are not radioactive nor dangerous.
Unstable isostopes are radioactive and have different mass of the element.
They are used to make plane bodies.
Some are used for electrical wires eg copper because they are good conductors of electricity.
Used in building materials.
used to make jewelry eg gold and silver<span />
<h3>Answer:</h3>
Oxidation number refers to a number given to an atom which shows the number of number of electrons lost (or gained, if the number is negative), by an atom of that element in the compound.
Hence oxidation number of following atoms in given reaction are:
In NaOH:
Na = +1
O = -2
H = +1
In H2:
H = 0
